This invention relates, in general, to solid state conductors, and more particularly, to a resonant high conductivity structure made from semiconductor materials.
Superconductivity results in a crystal lattice when electrons which are normally in energy levels within plus or minus k.sub.b T of a fermi energy (E.sub.F) collapse into an energy state which is approximately k.sub.b T.sub.c below E.sub.F, where T.sub.c is the critical temperature at which superconductivity occurs and k.sub.b is a vector defining a boundary of a brillouin zone for the crystal lattice. Electrons can only collapse by coupling or pairing into what is known as "Cooper pairs". Cooper pairs require each electron in an energy level to have equal momentum and spin which results in a tighter electron packing density than is possible under normal conditions. Paired electrons scatter with equal and opposite change in momentum, and thus no net loss in electron energy. Thus paired electrons carry charge in their energy level with zero resistance.
Accordingly, a key feature of superconducting materials is an ability to allow electrons to exist as paired electrons rather than fermions, which are responsible for normal resistive charge conduction. Much work has been done recently to develop materials in which paired electrons can exist at high temperatures. The present invention deals with a method of promoting the formation of paired electrons at temperatures where such pairing would not naturally occur.
Electrons in a crystal lattice have a characteristic coherence length which is determined by electronic and crystallographic properties of the crystal lattice. External forces such as heat and electromagnetic fields affect this electron coherence length. Electrons in normal conduction states repel each other, and will not come close enough to form pairs. Electrons in superconductors, it is believed, interact with lattice vibrations (phonons) to form pairs. Paired electrons are closer to each other than the electron coherence length. In naturally occurring superconductors electron-phonon interactions result in superconductivity at low temperature, where the electron coherence length is sufficiently long.
The present invention uses semiconductor materials to provide a synthetic lattice which is adapted to promote electron-phonon interaction, and in particular, to promote electron-phonon interactions which result in formation of paired electrons in materials and at temperatures where paired electrons do not normally exist.
A similar enhanced conductivity material is disclosed in co-pending application 07/411,780 by the same inventor as the present invention and assigned to the same assignee. This previous application is incorporated herein by reference.
Accordingly, an object of the present invention is to provide a new highly conductive material having a higher number of electron-phonon interactions.
Another object of the present invention is to provide an enhanced conductivity material having a resonant electron-phonon interaction process.
A further object of the present invention is to provide an enhanced conductivity material using a modulation doped superlattice quantum well.
Yet a further object of the present invention is to provide a resonant superlattice with quantum wells having phonon generators with an optical longitudinal phonon energy equal to spacing between two energy states.